Optimization of thermal treatment of carbon felt electrode based on the mechanical properties for high-efficiency vanadium redox flow batteries

Thermal oxidation is the easiest and most common way to generate oxygen functional groups on the surface of carbon felt, which improves the performance of vanadium redox flow batteries (VRFBs). Many researchers have reported the study of the various parameters for thermal oxidation. However, the aspect of reduction in the mechanical properties of the electrode has not yet been reported. In this study, optimized oxidation time and temperature were selected based on compression test analysis. The selection of optimized treatment temperature and time duration is based on the oxygen content and specific surface area. A carbon felt electrode oxidized at 600 °C for 30 min showed the best performance among the other treated electrodes. This study is mandatory at the laboratory scale and commercial levels, where the stability of the electrode for an extended period plays a significant role. Moreover, optimized pretreatment is essential for various other studies.